A trash removal apparatus is illustrated in U.S. Pat. No. 3,737,952 wherein overlapping cover plates are employed to provide for a reversely directed air release through the shroud formed by the cover plates. It has also been contemplated that the second of the plates facing in the direction of rotation of the carding element be set closer to the carding element than the first of the plates so as to form a self-expelling slot. The prior art also includes British Pat. No. 2,003,202 published Mar. 7, 1979 which illustrates the use of gaps formed between stationary flats positioned in edge-to-edge adjacent relationship with suction means for withdrawing air including dust and fly through the gaps.